GS1920 - ARP Broadcast Issues

Othacon

Hi all,

I'm new working with Zyxel switches and I'm having a really weird issue with them. I have an installation with 13 GS1920 switches and their configuration is pretty simple, one Vlan with an SVI, RSTP enabled and configured and Multicast Enable and configured.
The switches connected to a Cisco Core switch where all the routing happens, but this is happening, when I ping a switch the first 2 sometimes 4 pings time out and then the switch starts replying, all good since the arp needs to populate but the weird is, if I don't use the switch or don't communicate for 2 minutes, if I do another ping the same thing happens, it times out the first 2 to 4 pings and then I get a reply. 
Did a ping directly from the core without the packet being routed and the same happens. Did a wireshark capture directly from the Cisco and could see that the Cisco sends the packet but doesn't get a response, then an arp broadcast is received by the Cisco from the Zyxel, where it asks where the device is, then the Cisco replies to the request and then the pings start to work on e again. Basically the Cisco knows where to send the packet but then the Zyxel switch as to ask every single time if no connection is executed within two minutes. The cam table is configured for 5 minutes so I can't understand what is happening in here.
Please any ideas? All the switches are doing the same.

Thank you

Zyxel_Chris

@Othacon,
May I know if the cisco and our switch are located in the same management subnet?

Othacon

Hi @Zyxel_Chris ,

Indeed, the Cisco is a 9300 with Vlan 41 configured, and the port that connects to the Zyxel is configured as access and the IP of the SVI is 10.6.41.254. The Zyxels have all the ports configured for Vlan 41 and all untagged  (the simplest of the configurations) and they are configured with the gateway of the Cisco and the IPs of the Zyxels starts in 10.6.41.41 till 10.6.41.53

Thank you

Zyxel_Chris

@Othacon,
We have tried to reproduce this issue unfortunately, didn't see the problem, in order to verify this case, could you please help to collect the tech support file in GS1920, Management>Maintenance.
Also could you please send the private message to me about the packet you have mirrored before, please let me know the timestamp when it occurred.